LOL the “snark” was aimed at me, not you! So don’t worry about it.
The question is, what do you need to do differently if she is in foal? Presuming you are feeding adequately for either (and you’re right, she looks great now), and she is a MINIMUM of 8 months in foal and a maximum of 10 months (since she has not yet started to make a noticeable milk bag), basically the only difference in her care is the pre-foaling tetanus shot, one month out from her PRESUMED foaling date. Make sure she is getting enough protein and mineral supplementation in her diet, but don’t over feed her. She could have been given injections to guard her from spontaneous abortion from rhino infections, but she hasn’t had those, and has not aborted (presuming she is in foal) so far, and since she has been moved around quite a bit (auction etc), she may have good resistance already, or else she would have aborted already. She may yet abort, for any of a number of reasons, rhino being only one of those reasons. You could consider vaccinating her now, ask your vet about that, but she will only need one more (the 9 month one) if you decide to do it at all. Since a mare can go over or under her expected foaling date (if you had a date of last cover), this is always an estimate. And a vet can not pin it down any closer than this, at this stage. It will become apparent, if she is pregnant, and yes, she does look like she could be. IF she has something nasty in there, like twins (too late to tell this now), or a tumour, or something that is not a foal, again, there isn’t a lot you can do about it now, other than send her for $20,000 worth of surgery. If your plan is that you are going to send her out to foal, to someone with more experience foaling out mares, this is a good plan, and you can start looking for a good place now, in case she does continue to look like a foal is coming at some point. You would need to send her before she gets too close to foaling, don’t wait until she is leaking milk. But keep in mind that shipping very pregnant mares carries risk too… it is done successfully most of the time.
Many people plough many thousands of dollars to get a mare pregnant, and keep her pregnant, and in an attempt to avoid disaster. Sometimes it is money well spent and a successful birth is the result. Other times, that money is flushed down the toilet, and disaster happens anyway. Other mares (like perhaps yours) get loose with a stallion for one day, come back pregnant from a live cover, and nobody knows, and if they get regular decent feed and mineral access (especially in the later months of the pregnancy) , and produce a perfectly healthy foal by themselves, and raise it well. There is no way to guarantee success, each owner simply does what they feel is right, and what they can afford. But multiple vet visits and vet work now, and attempting now to visualize a foal in utero, or not, at this late date does nothing to help, other than to help to send your vet’s kid through university.
Good luck! She’s a cute mare and sounds like a sweetheart too, I hope it was an acceptable stallion, and that you have success. You will likely love it, and it will be cute, no matter what the stallion may have been, and you will find a use and create value for this little bundle of joy, if it successfully gets born. Let us know what your vet thinks, and when or if you get a foal.